Ranked by evidence
Best supplements for PCOS (polycystic ovary syndrome)
PCOS needs a diagnosis and a treatment plan from a doctor, and no supplement replaces metformin, ovulation induction or lifestyle care. Myo-inositol is the only supplement with a moderate grade for PCOS, covering insulin resistance, testosterone, cycle regularity and ovulation, and even the review behind the 2023 international guideline called the evidence limited and inconclusive. Picks are ranked by the strength of the evidence for PCOS outcomes, not by popularity.
Picks are ranked by the strength of published evidence for this goal in otherwise healthy adults. A persistent symptom needs a clinician's evaluation, and no supplement on this list replaces treatment.
Evidence last reviewed: October 2026
Solid options
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Inositol (Myo-Inositol) | Moderate evidence | insulin resistance, cycles and ovulation | Across 26 randomised trials it lowered fasting insulin and HOMA-IR and improved testosterone and menstrual regularity, broadly like metformin but with fewer gut side effects. The 40:1 myo to D-chiro ratio on many labels has not been shown to beat myo-inositol alone. | View |
Situational
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Folic Acid (Vitamin B9) | Strong evidence | if you are trying to conceive | It does nothing for PCOS itself, but 400–800 mcg a day from at least one month before conception prevents neural tube defects. Many inositol trials paired the two. | View |
Popular for this goal — but the evidence says skip
- D-Chiro-Inositol Limited evidence
The enthusiasm rests on one small 1999 trial that other groups did not reproduce, and doses of 600 mg a day and above have been linked to worse egg quality in IVF settings.
- Spearmint Extract Limited evidence
The PCOS studies used two cups of spearmint tea a day for 30 days, lowered free testosterone without measurably improving hirsutism, and the capsules sold are a different product.
- Maitake Limited evidence
Its PCOS evidence is one unblinded trial of 80 women using a purified fraction that ordinary capsules do not match, and it was never replicated.
- Fertility Blends Limited evidence
Cochrane found very low-quality evidence for myo-inositol on live birth, and blends often dose their ingredients at 10–40% of the studied amounts.
- Marjoram Limited evidence
The only study was a one-month pilot of marjoram tea in 25 women that measured blood markers, not cycles or ovulation.
- Shatavari Limited evidence
There is no adequately powered placebo-controlled trial of shatavari for PCOS, cycle regularity or conception.
Our verdict
If you want to try one thing, take myo-inositol at 2 g twice daily for 12–24 weeks and judge it on your cycles and lab results with your doctor. If you are trying to conceive, add folic acid. Skip standalone D-chiro-inositol, spearmint, maitake, marjoram and fertility blends.